The invention relates to a head gate of the type comprising at least one tubular structural element and extending in a main plane.
The head gate is a special gate constituting a barrier making it possible to hold farm animals in position, limiting their movements by holding their neck between two parallel vertical bars.
Each structural element comprises a frame in which a substantially rectilinear movable bar is mounted so as to pivot, substantially half-way along its length, about an axis perpendicular to the main plane.
This movable bar can consequently adopt three positions:
an open position providing a space between substantially the top half of the movable bar and the frame, thus enabling the animal to pass its head through the head gate element;
a closed position in which the movable bar is substantially vertical and parallel to an element of the frame, preventing the animal from withdrawing its head is from the head gate element;
a release position providing a space between substantially the bottom half of the movable bar and the frame, thus enabling the animal, for example in the event of falling, to withdraw its head from the head gate element through the bottom.
Each head gate element makes it possible to accept one animal, the head gate being formed by the assembly, in the same plane, of as many elements as there are animals.
In the prior art, the head gate elements comprise means of locking the aforementioned movable bar.
By way of example and as described in the patent FR 2 750 292 of the present applicant, FIG. 1 is a partial view of a head gate element showing one of these devices for locking the movable bar.
These locking means usually comprise a hollow control bar 113 mounted on a top part 103 of the frame 101 and a locking fork joint 111 fixed at the top end 110a of the movable bar 110. The locking fork joint 111 coming to straddle the control bar 113.
The control bar 113 is able to move in rotation about its longitudinal axis and has, over its length, projections 121, 122, 123 intended to cooperate with a slide 115 carried by the locking fork joint 111.
The locking fork joint 111 comprises two substantially parallel walls 111a, 111b, extending in the longitudinal direction of the movable bar 110, in which facing oblong holes 130a, 130b are formed, also extending in the longitudinal direction of the movable bar 110.
The slide 115, extending between the walls 111a, 111b of the locking fork joint 111 and being guided in translation in the oblong holes 130a, 130b, cooperates under the effect of its own weight with the projections 121, 122, 123 on the control bar 113 in order to lock the movable bar 110 in its closed position.
The head gate described in the document FR 2 750 292 does not give complete satisfaction.
This is because, the slide 115 being guided in translation by the two oblong holes 130a, 130b, it is necessary for the fixings 131a, 131b to be projecting from the external faces of the locking fork joint 111 in order to effect the guidance.
It is possible to limit the size of these projecting parts 131a, 131b but not to omit them since they are made obligatory by the use of opening-out oblong holes 130a, 130b as guides for the translation movement of the slide 115.
These projecting parts 131a, 131b make it possible to lift the slide 115 from the external faces of the locking fork joint 111 giving the possibility for the animal in place in the head gate to lift the slide 115 with its muzzle and thus to put the head gate element in the open position in order to release itself.
In addition, the document EP-A-1 040 753 describes a head gate comprising a control bar having notches intended to receive a sliding shaft, thus enabling the movable bar to be locked. In this document also, the sliding shaft has parts projecting from the external faces of the blocking fork joint.
The aim of the invention is to mitigate these drawbacks of the prior art by providing a head gate element provided with a device for locking the movable bar which is more secure and less expensive to manufacture.
The invention also aims to provide a precise translational movement of the slide by preventing unwanted releases.
To this end, the object of the invention is a head gate element comprising:
a substantially flat frame;
a substantially rectilinear movable bar mounted so as to pivot on a shaft fixed to the said frame and substantially perpendicular to the plane, so that the movable bar can be situated in two extreme inclined positions, namely an open position and a release position, as well as in an intermediate so-called closed position in which the movable bar is substantially vertical;
fixed rigidly to one end of the movable bar, a locking fork joint formed by two plates, receiving a transverse slide able to move in translation in the direction of the movable bar;
a control bar able to move in rotation about its longitudinal axis in order to control the possibilities of the movable bar in the aforementioned three positions, this control bar being fixed in translation to the top part of the frame and extending between the two plates of the locking fork joint.
According to a general definition of the invention, the control bar comprises locking means arranged to cooperate with the slide of the locking fork joint, the slide being guided in translation by guidance means situated on the internal face of each of the plates.
The external faces of the locking fork joint are thus free of any projecting translation device, preventing the possibility of the animals lifting the slide.
In one embodiment, the guidance means comprise profiled sections situated on the internal face of each of the plates, the said profiled sections having their longitudinal axis substantially parallel to the longitudinal axis of the movable bar.
The use of these profiled sections makes it possible to obtain robust runners at a low production cost.
More precisely, two profiled sections are fixed to the internal face of each of the plates, the two profiled sections of one and the same plate being separated from each other so that the slide can slide along this distance.
This type of guidance has sufficient precision for the application in question.
It can however be improved by providing, on the slide, stops arranged so as to slide against the profiled sections whilst preventing the slide from coming into contact with the two plates, thus preventing its wedging during its translation movement.
In a particular embodiment, the slide comprises a metallic core and a polymer is envelope.
The metallic core enables the slide to attain a weight providing good functioning of the locking means and the polymer envelope makes it possible to obtain a covering with a low coefficient of friction in which it is also possible to form the stops described above.
The measures described up to now allow optimum guidance of the slide and secure locking of the movable bar.
It is also possible to propose a control bar with no welds and providing better locking of the slide.
To this end, a head gate element is provided of the type described above in which the locking means carried by the control bar comprise a transverse notch arranged so that the slide can fit therein when the movable bar and the control bar are in the closed position.
According to one possible embodiment, the control bar is solid and produced from a material belonging to the group formed by aluminium and its alloys.
The bar can be produced from a strong lightweight metallic material, other than galvanised steel, made from copper or bronze. The bar can also comprise a metallic core and a covering made of plastics material.
The result is firstly the possibility of manufacturing the control bar from a solid profiled section in which a transverse groove will be machined in order to form the said notch.
It is no longer necessary to carry out welding, the control bar thereby being more simple and less expensive to manufacture.
The slide can cooperate either with a control bar provided with a notch or welded projections, and can be adapted to existing head gates.
According to one embodiment, the locking means carried by the control bar also comprise an inclined flat on the control bar so as to form a slope, the bottom of the said slope opening out in the notch and the top of the said slope being oriented towards the open position of the movable bar so that the slide, when the movable bar passes from the open position to the closed position, can slide along the control bar and then along the slope and then fit in the notch.
This slope facilitates the locking of the movable bar by obliging the slide to fit in the notch.
This is because, when the movable bar is actuated and the slide is at the bottom of the slope, the said slide is then already partially engaged in the notch and, coming to abut against the side of the notch opposite to the flat, can only fit in.
In one embodiment, the head gate element also comprises a safety locking device for the closed position of the movable bar, the said device consisting of a removable pin connecting, when it is in place. The locking fork joint and the frame.
The various embodiments can also advantageously encompass safety equipment vis-a-vis the animals.
In particular, the movable bar of the head gate element according to the invention can also comprise, towards its end part opposite to the locking fork joint, means forming a counterweight able to automatically return the movable bar into its open position when it is not being acted on.
This prevents injury to or strangulation of the animals since the head gate can go into the closed position only by means of a deliberate action by the user.
In a variant, a bar connects the said end of the movable bar to the means forming a counterweight so as to prevent the collars of the animals becoming attached to the movable bar.
In another embodiment, these means forming a counterweight extend in a plane parallel to the main plane of the head gate so that they also enable the passage between the bottom part of the movable bar and the frame to be blocked off, on the side which is not provided for the animal to insert his head therein.
Likewise, the movable bar can also comprise, close to the locking fork joint, means of blocking the passage between the top part of the movable bar and the frame, also on the side which is not provided for the animal to insert its head therein.
By thus blocking the openings not designed for the passage of the head of the animal, risks of jamming are greatly reduced.
In another embodiment, means of controlling the rotation of the control bar are provided.
As a variant, it is also possible to provide an end of rotational travel member, as well as means of locking the control bar for angular position.